X-ray ejecta kinematics of the Galactic core-collapse supernova remnant G292.0+1.8

TL;DR

This study uses high-resolution X-ray spectroscopy to analyze the 3D structure and kinematics of ejecta in the supernova remnant G292.0+1.8, revealing insights into its explosion dynamics and progenitor characteristics.

Contribution

First detailed 3D kinematic analysis of ejecta in G292.0+1.8 using Chandra HETGS data, estimating ejecta velocities, remnant structure, and progenitor mass.

Findings

Ejecta knots exhibit radial velocities between -2300 and 1400 km/s.

Ejecta shell has an angular thickness of about 90 arcseconds (~3 pc).

Estimated progenitor mass is less than approximately 35 solar masses.

Abstract

We report on the results from the analysis of our 114 ks Chandra HETGS observation of the Galactic core-collapse supernova remnant G292.0+1.8. To probe the 3D structure of the clumpy X-ray emitting ejecta material in this remnant, we measured Doppler shifts in emission lines from metal-rich ejecta knots projected at different radial distances from the expansion center. We estimate radial velocities of ejecta knots in the range of -2300 <~ v_r <~ 1400 km s^-1. The distribution of ejecta knots in velocity vs. projected-radius space suggests an expanding ejecta shell with a projected angular thickness of ~90" (corresponding to ~3 pc at d = 6 kpc). Based on this geometrical distribution of the ejecta knots, we estimate the location of the reverse shock approximately at the distance of ~4 pc from the center of the supernova remnant, putting it in close proximity to the outer boundary of the radio pulsar wind nebula. Based on our observed remnant dynamics and the standard explosion energy of 10^51 erg, we estimate the total ejecta mass to be <~ 8 M_sun, and we propose an upper limit of <~ 35 M_sun on the progenitor's mass.